Mining machine with pivotally mounted and opposed elongated cutters



DeC- 6, 1966 R. o. BREDTHAUER 3,290,095

MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS Filed May 28, 1964 1o sheets-sheet 1 RAYMOND O. BREDTHAUER IN VEN TOR ATTORNEY Dec. 6, 1966 R. o. BREDTHAUER MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS lO Sheets-Sheet 2 Filed May 28, 1964 FIGURE 5'A FIGURE 6A FIGURE fs-B RAYMOND O. BRED'THAUER INVENTOR.

BYo/QKM ATTORNEY Dec. 6, 1966 R. o. BREDTHAUER MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS lO Sheets-Sheet 3 Filed May 28, 1964 FIGURE 7-A FIGURE 7-C RAYMOND O. BREDTHAUER INVENTOR.

ATTORNEY Dec. 6, 1966 R. o. BRI-:DTHAUER MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS Filed May 28, 1964 lO Sheets-Sheet 4 RAYMOND O. BREDTHAUER INV ENTOR,

AT TORN EY DeC- 6, '1966 R. o. BREDTHAUER 3,290,095

MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS Filed May 28, 1964 lO Sheets-Sheet 5 FIGURE 8B RAYMOND O. BREDTHAUER INVENTOR.

Bmg/My ATTORNEY Dec. 6, 1966 R o. BRI-:DHAUr-:R 3,290,095

MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS Filed May 28, 1964 l0 Sheets-Sheet 6 FIGURE IO RAYMOND O. BREDTHAUER INVENTOR.

AT TGR NEY Dec 6, 1966 R. o. BREDTHAUER 3,290,095

MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS Filed May 28, 1964 lO Sheets-Sheet '7 FIGURE FIGURE RAYMOND Of BREDTHAUER I NVENTOR ATTORNEY R. O. BREDTHAUER MINING MACHINE WITH PIVOTALLY MOUNTED AND Dec. 6, 1966 OPPOSED ELONGATED CUTTERS Filed May 23, 1964 lO SheeCS-Sheet 8 FIGURE I3 FIGURE I4 FIGURE I5 RAYMOND O. BREDTHAU ER INVENTOR.

ATTORNEY Dec. 6, 1966 R. o. BRl-:DTHAUER MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS Filed May 28, 1964 lO Sheets-Sheet 9 RAYMOND O. BREDTHAUER INVENTOR,

www y ATTORNEY DGC- 6, 1966 R. o. BREDTHAUER 3,290,095

MINING MACHINE WITH PIVOTALLY MOUNTED AND oPPosED ELONGATED CUTTERS Filed May 28, 1964 l0 Sheets-Sheet 10 FIGURE I7 RAYMOND O. BREDTHAU ER INVENT OR.

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ATTORNEY United States Patent() 3,290,095 MINING MACHINE WITH PIVOTALLY MOUNTED AND OPPOSED ELONGATED CUTTERS Raymond 0. Bredthauer, Houston, Tex., assgnor to Hughes Tool Company, Houston, Tex., a corporation of Delaware Filed May 28, 1964, Ser. No. 370,802 7 Claims. (Cl. 29957) This invention relates generally to mining or tunneling machines and moreparticularly concerns a machine having cutters which operate in a novel .and advantageous manner.

Many prior art mining machines have the cutters arranged to frontally attack the tunnel face in a manner causing large longitudinal reactive forces to bear against the machine. To resist these forces and to prevent slippage between the machine and the tunnel floor, it is frequently necessary to insert wall jacks lbetween the machine and the tunnel walls, floor and/ or ceiling. Or it is sometimes necessary to use more complex apparatus and techniques to prevent slippage, which if not prevented can drastically decrease the drilling rate of the machine.

Other prior art machines use elongated cutters pivotally mounted to operate in a substantially horizontal plane. One example of this type machine may be seen in the U.S. Patent of Gonski et al., No. 3,121,558. While such machines have been successful to a large degree and representrvaluable contributions to the earth boring art, they nonetheless have some of the disadvantages of other prior Iart machines. For example, large longitudinal reactive forces are imposed on such machines because of their mode of operation. `Consider the fact, for illustration of this point, that the elongated cutters of such machines must be thrust longitudinally a large distance into the tunnel. face before they are rotated pivotally. During the initial longitudinal thrust stage, large longitudinal reactive forces are imposed on the machine, as is common in other prior art machines. This is a disadvantage which limits the eiciency and thus the effectiveness of these machines.

It is an object of this invention to overcome to a large degree the disadvantage explained above of prior art machines. More specifically, it is an object of this invention to provide a tunneling or mining machine which reduces the longitudinal reactive forces imposed on the machine by using a novel cutting arrangement and mode of operation, which reduces the longitudinal thrust stage. Another object is to provide a machine having elongated cutters which move through the tunnel face in a direction substantially perpendicular to the tunnel and on a ledge formed therein by an initial longitudinal thrust of the cutters while simultaneously rotating them about their longitudinal axes. This results in a cutting motion which produces the majority of reactive forces in a substantially vertical plane, thus reducing the longitudinal reactive forces.

In accordance'with the foregoing objects the invention may be broadly described as a tunneling or mining machine having fr-ontally mounted elongated and opposed` 3,290,095 Patented Dec. 6, 1966 The invention will be more readily understood with reference to the following detailed description and the accompanying drawing, in which:

FIGURE l is a partially schematic side elevational view showing the elongated cutters of the present invention frontally mounted on a commercially available tractor,

FIGURE 2 is a sectional end view of the invention as seen looking in the direction of the lines and arrows 2-2 of FIGURE l, showing more clearly the initial disposition of the elongated cutters,

FIGURE 3 is a partial sectional view as seen looking along the lines and arrows 3 3 of FIGURE 2, showing a hydraulic cylinder and lever arms mechanism for pivotally moving the elongated cutters,

FIGURE 4 is a fragmentary sectional view taken as indicated by the lines and arrows 4-4 of FIGURE 1, showing a lower supporting framework and more details of the initial disposition of the elongated cutters and their driving mechanisms,

FIGURES 5-A and 5-B are perspective views of a tunnel face, illustrating in schematic form the paths the elongated cutters follow as they rotate pivotally, and the paths the cuttings from the tunnel face follow as they progress toward and through a horizontal conveyor,

FIGURES 6A and 6-B show a roof support and its movable upper member which adds operational stability to the tunneling machine,

FIGURE 7-A is a perspective view of an embodiment of the present invention having two pilot bits, two elongated cutters in the form of angers, and mechanisms for rotating them pivotally and about their longitudinal axes,

FIGURES 7-B and 7-C show alternate embodiments of the elongated cutters, illustrating that the invention is not limited to cutters having the auger design of FIG- URE 7-A, y

FIGURES 8-A and 8-B are fragmentary sections taken longitudinally through one side of the FIGURE 7-A embodiment to show a preferred power train that may be used in practicing the invention,

FIGURE 9 is a sectional view as seen looking along the lines and arrows 9-9' of FIGURE 8-A. This figure shows the sprocket and ohain drive which is attached to a tractor power take-off shaft to divide the power train into two components,

FIGURE 10 is a sectional view taken as looking along the lines and arrows 10--10 of FIGURE 8-A. This view shows the configuration of the shaft mounted speed reducers,

FIGURE 1l is a sectional view, taken as seen looking along the lines and arrows 11-11 of FIGURE 8-A, and this view shows the clutch mounted lever arms and the hydraulic cylinder disposed therebetween which cooperate to pivotally rotate the elongated cutters,

FIGURE 12 is a sectional View as seen looking along the lines and arrows 12--12 of FIGURE 11,

FIGURE 12-A is a fragmentary sectional view which shows in greater detail the clutch configuration of FIG- URE l2,

FIGURE 13 is a sectional view taken as seen .along the lines and arrows 13-13 of FIGURE 8-A, showing the disposition and configuration of the cusp breakers,

FIGURES 14 and l5 are sectional views as seen looking in the direction of the lines and arrows 14-14 and 15-15 of FIGURES 8-B. These views show the speed reduction unit whi-ch is adjacent to the pilot bit,

FIGURE 16 is another side elevational view, partly in section, which shows the invention mounted in a shield propulsion unit, and

FIGURE 17 isa sectional view as seen as looking in the direction of the lines and arrows 17-17 of FIGURE 16 to show in greater detail the configuration of the shield and the disposition of the various mechanisms supported therein.

Referring to FIGURES 1 through 4 of the drawing to explain first the salient features of the invention, notice that there are three separate cutters frontally mounted on the tractor 39. The foremost cutter 26 is a pilot bit which rotates about shaft 21. In addition to pilot bit 20 there are a pair of elongated cutters 22 which rotate about their longitudinal axes 40 and which also rotate pivotally, as may be seen in the sectional end view illustrated in FIG- URE 2. Arrows 49 indicate the pivoting of cutters 22 in a vertical plane.

Before proceeding further with a detailed structural description, reference is made to FIGURES -A and 5-B, which when considered in conjunction with FIGURES 1 through 4 `and the brief explanation above will simplify further study of the invention. Notice that the elongated cutters 22 shown in FIGURES 1 and 2, when rotated pivotally and oppositely after an initial incremental forward thrust of tract-or 39, form two shelves 52 in the tunnel face 51. The cutters 22 continue to pivot downwardly until they reach a vertical position 180 degrees removed from their initial position shown in FIGURE 2. Then they are retracted, thrust another increment into the tunnel face (now designated by numeral 50 in FIGURES 5-A and 5-B), and the operation is repeated. A more detailed explanation of the operation of the invention and the advantages to be gained -by its use will be given later. This initial explanation is given merely to provide a basis for a more thorough initial understanding of various mechanisms used to accomplish the desired results.

Referring once again to FIGURES 1 through 4, where the mechanism for rotating -both the pilot bit 20 and the elongated cutters 22 are shown, the detailed description is continued. Notice that the pilot bit 20 and its shaft 21 are connected to a speed reducer 26, which in turn is connected to the tractor power take-olf shaft 27 via a chain or belt drive mechanism 42, the function of which is to divide the power available from the tractor 39 into three components. Thus, the speed reducer 26 (actually three speed reducers, one for each power component), in addition to providing the proper rotational speed to pilot bit 20, rotates at the proper speed the elongated cutters 22 about their longitudinal axes 40 with the aid of clutches 24 and gear boxes 23.

To rotate pivotally the elongated cutters 22, there are a pair of lever arms 25, which are initially disposed vertically and parallel to cutters 22. In this embodiment the cutters actually have an intermittent pivotal movement rather than a continuous movement. This action results from the use of a hydraulic cylinder 35 interposed between lever arms 25, as is clearly illustrated in FIGURE 3. The clutch 24 at the lower end of the lever arms 25 functions as a ratchet 4mechanism which disengagedly connects the lever arms 25 to the cutters 22. Assuming that each lever arm 25 and each cutter 22 is vertically disposed and rigidly connected by means of clutch 24, the extension of hydraulic cylinder 35 forces both of them to pivot a predetermined distance toward the horizontal. Then the clutch 24 is disengaged and hydraulic cylinder 35 is retracted, drawing lever arms 25 (but not the cutters 22) back to the initial vertical position. Then the clutch 24 is thrown to engage lever arms 25 and cutters 22 once again, so that the step above may be repeated. Thus, the cutters 22 intermittently rotate across the entire tunnel face.

The elongated cutters 22, the pilot bit 20, and all the above described mechanisms used to -operate them, are supported primarily by the main support bars 28, which extend longitudinally along the sides of the tract-or. A plurality of transverse support bars 29 and 29 are connected to main support bars 28, and it is these bars that contact and directly support the various power train mechanisms described above. A hydraulic cylinder 30 is connected to main support bar 28 to provide vertical ad- 4 justment of the pilot bi-t 20 and the elongated cutters 22 with respect to the tractor 39. Main support bars 28 are mounted pivotally as is designated by numeral 43 to permit such vertical adjustment. Furthermore, angular adjustment of the pilot bit 20 and elongated -cutters 22 is accomplished by the use of hydraulic cylinders 31, which connect the transverse support bar 29 and the speed reducer 26. Notice that the forward transverse support bar 29' has on each end a pivotal mounting 44, enabling angular movements with respect to the tractor 39 of the pilot bit 2t), the elongated cutters 22, and the various power train mechanisms in response to the action of hydraulic cylinders 31. This facet of the invention enables the machine to alter its vertical direction of travel during the tunneling or mining operation in a convenient and simple manner.

ventional operation of the tractor 39 and are not described for that reason.

Disposed above the tractor 39 is-a roof support 32, which in this embodiment supports an axially movable roof 33, which is adjusted forwardly and rearwardly by hydraulic cylinders 34, and adjusted vertically by hydraulic cylinders 41. The purpose of the roof support 32 and axially movable roof 33 is to provide better support for the machine, especially while the cutters 22 move through the cutting lcycle described briefly above. To illustrate this function of the axially movable roof 33, FIG- URE 6-A shows the cutters 22 in their initial vertical disposition. As the cutters 22 pivot toward a horizontal position, as is shownin FIGURE -6-B, the movable roof 33 is thrust forward by the action of hydraulic cylinders 34 to a position between the cutters 22, thereby furnishing support to the tunnel roof over the cutters. Since many of the reactive forces imposed on the machine act in a vertical plane defined by the longitudinal axes 40 of the cutters 22, the provision of a movable roof 33 greatly increases the operational stability of the machine.

A conventional cuttings conveyor 36 is disposed below the tractor and between tracks 37 to remove the cuttings. A runway fabricated of sections 38 is provided to support the tracks 37 and is extended as the tunnel progresses to keep the tractor 39 level.

When cutters 22 of the opposed auger type are used, as are shown in FIGURES 1 and 2, the cuttings from the face 'of the tunnel are removed as described previously and as may be seen in FIGURES 5-A and 5-B. The cutters 22 move the cuttings toward conveyor 36 and cuttings chute 53 and therefore away from the machine. This action -of the cutters is achieved even after the cutters 22 move below the horizontal plane, as is shown in FIGURE 5-B, and this is one of the advantages of using elongated cutters 22 having an auger configuration.

To explain in more detail a practical power train mechanism that may be used to rotate the elongated cutters both pivotally and about their longitudinal axes, reference is made in FIGURES 7-A, S-A and 8-B. This embodiment is similar to that shown in FIGURES l through 4 except it has two pilot bits instead of one. As illustrated, a power take-off shaft 60 on the front of a tractor drives a sprocket 61 which is connected by means of chains 62 to jack shafts 6W by means of sprockets 63, as may be seen more clearly in FIGURE 9. The purpose of this mechanism is to divide the power train into two components, each of which ultimately rotates an elongated cutter and a pilot bit 111 as is shown in FIGURE 7. Jack shaft 6@ (referring now to only one side of the power train as is illustrated sectionally in FIGURES 8-A and 8-B) is connected to a support bearing 61 and then to a universal joint 66. A shaft 64 extends from universal joint 66 into the shaft mounted speed reducer 67.

As is shown more clearly in FIGURE l0, the speed reducer 67 drives an inner drive shaft 69 by means of a series of gears (not shown). There are many types of speed reducers and the commercially available shaft Changes in the direction the machine travels during the tunneling operation are controlled by the conmounted type is shown merely because it is a great weight saver. Notice that shafts 64 and 69 are the only support needed for both speed reducers 67. Since the torques imposed on these members must be counteracted, turnbuckles 130 are attached t-o support frame 132 and to ears 131 which protrude from the speed reducer 67.

Referring again to FIGURE 8-A, the inner drive shaft 69 is supported by pillow block 70. In front of pillow block 70 is a second pillow block 72 which supports an outer, independently rotatable shaft 71 that surrounds inner drive shaft 69. Outer shaft 71 is connected to a clutch 73, or more specifically, to the inner member 75 of clutch 73. The outer member 74 of the clutch 73 is relatively rotatably supported on outer shaft 71 through bearing 96, and does not pivot with 71 until the clutch is engaged. This may be seen more clearly in FIGURES l1, l2, and l2-A where it may be seen that lever arms 76 are connected to the outer members 74 of clutch 73. At the upper end of lever arms 76 is a hydraulic cylinder 77 which pivots the lever arms 76 to a predetermined angular position. With clutch members 74 and 75 engaged, the elongated cutters 85 of FIGURE 7-A piv-ot with lever arms 76. Then the members 74 and 75 of clutch 73 are disengaged while lever arms 76 are retracted for another cycle, as has been described in connection with FIGURES l through 4. To eliminate the need for axial movements in the clutch 75, atcommercial pneumatic clutch is clearly illustrated in FIGURE l2-A. There, an inflatable rubber tube 78 is secured to outer member 74 and has on its innermost surface shoes 78. When air is forced into rubber tube 78, the shoes 78 are forced against inner member 75, thus securing shaft 71 and cutters S5 to lever arms 76.

Supported by frame support 79, as are the outer members, is a cusp breaker 80. As is apparent in FIGURE 13, a wedge of formation will be left between the two pilot bits 111 of FIGURE 7-A. When one pilot bit is used, as is shown in the FIGURE l embodiment, it is not necessary to use a cusp breaker Si), but it is beneficial in embodiments having two pilot bits in order to prevent a formation build-up that would impede forward progress of the machine.

Referring again to FIGURE S-B, a thrust bearing 81 is disposed in gear box 83 and around the inner drive shaft 69 to take the axial loads transmitted through the first bevel gear 82 inside gear box 83. A second bevel gear 84 is secured to elongated cutter shaft 85 and engages the first bevel gear 82. Shaft 85 `is supported by an upper tapered roller bearing 86 and a lower tapered roller bearing 87, both of which are disposed in gear box 83. These bearings resist forces which are transmitted through the rotatable cutters 89, auger ights 8S, and elongated cutter shaft 85. A third bevel gear 90 is connected to gear reduction shaft 91, which is supportd by a tapered roller bearing 92. Shaft 91 is connected to a clutch 93 inside housing 102 to control the rotational movement of the forward end 91 of the shaft 91. A spherical roller bearing 94 supports shaft 91 and prevents axial movement of the pinion 100 of the first spur gear set, which is shown in FIGURE S-B but more clearly in FIGURE 14. Spur gears 101 engage pinion 100 and are supported by gear shafts 103. Bearings 104 support gear shafts 103, which have on their opposite ends a set of pinion gears 105 in a second gear set (shown more clearly in FIGURE l5). Spur gear 107 is connected to pilot bit drive shaft 108, which in turn is supported by bearing 110.

Connected to drive shaft 108 through flange 112 is a pilot bit 111. Although the particular type pilot bit is immaterial in practicing the invention, FIGURE 8-B illustrates a bit having a central shaft 113 which connects flange 112 to at least one but usually a series of plates 115. For structural strength there are a plurality of struts 114 which connects central shaft 113 to the plates 115. Disposed on the plates 115 are a number of cutter assemblies 116, the function of which is to remove formation from the face of the pilot hole 120.

To remove the cuttings from the pilot hole there are a series of fragmentary auger flights 117 (see FIG. 7-A) disposed between the cutter assemblies 116 as is taught in the application of Warren T. Iones, Serial Number 325,095, filed November 20, 1963, and now Patent No. 3,172,489. Extending rearwardly from the plates is a cylindrical support 118 that protects the various drive train mechanisms from the abrasive or otherwise detrimental action of the cuttings. Auger flights 119 are wrapped around shield 118 t-o move the cuttings rearwardly along the pilot hole and into a conveyor, such as the conveyor 36 of FIGURE l.

It is apparent that the overall operation of the elongated cutters 8S and the'pilot bits 111 of FIGURE 7-A is basically similar to the previously described operation of the embodiment illustrated in FIGURES 1 through 4. To enable a better understanding of the various mechanisms described in connection with FIGURE 7-A, however, an expianation of the operation of that embodiment will be given.

Therefore, notice that the pilot bits 111 of FIGURE 7 are driven by the gear reduction unit enclosed in housing 95, which may be seen in FIGURE 8-B. The clutches 93 that joins the gear reduction drive shaft 91 at its forward end 91 is provided to disengage the pilot bit 111 while the elongated cutters 85' are being rotated through their vertical paths. This is beneficial from an efficiency point of view since forward longitudinal motion is halted while the elongated cutters 85' are being pivoted in the vertical plane. Rotational movemnt of pilot bits 111 is ineffectual and should be ceased for this reason.

The pivotal movement of the auger central shaft 85 is accomplished by the rigid engagement of gear box 83 to outer rotatable shaft 71, which is connected to the inner member 75 of clutch 73. When the inner member 75 of clutch 73 is engaged with the outer member 74, then any pivotal movement of lever arms 76 will cause a similar pivotal movement of the auger centra-l shaft 85. Consequently, when clutch members 74 and 75 are disengaged the lever arms 76 may be returned to their initial vertical position (shown in FIGURE 7), but the auger central shafts 85 will be left at the angular disposition to which they were carried by the pivotal movement of lever arms 76. Thus it may be seen that the auger central shafts 85 are ultimately indexed from the upward vertical position (as seen in FIGURE 7) 180 degrees to a downward vertical position (not shown). Consequently, successive or incremental sections of the tunnel face may be removed with minimum longitudinal reactive forces bearing against the machine.

The only large longitudinal reaction forces are created Vduring the initial step when the elongated cutters 85 and pilot bits 111 are being thrust against and buried into the tunnel face. During this step the pilot bits 111 are rotating as are the auger central shafts 85 to achieve maximum cutting efficiency. After the initial step, the rotation of pilot bits 111 is ceased by disengalging clutch 93, and then the indexing of the elongated cutters 85" is accomplished through the cooperation of hydraulic cylinder 77, lever arms 76, and clutch 73.

Since it is now apparent that the invention relates primarily to a novel arrangement and configuration of elongated cutters, there are obviously a wide variety of suitable mobile carriages. The tractor 39 of FIGURE 1 is a convenient carriage but it has disadvantages, principally its lack of rigidity and the fact that the tracks are far removed from the center of gravity of the power train mechanisms, the elongated cutters 22, and the pilot bit 20.

A much more rigid carriage and one having better overall weight distribution is designated by the numeral in FIGURES 16 and 17. Actually, carriage 140 is cornmonly called a shield and is already known generally in the tunneling art. The shield 140 slides along the tunnel floor, being pushed forward when desired by the action of plural hydraulic propulsion jacks 146. External framework 141 is jointed to internal framework 142 as is shown more clearly in FIGURE 17. The propulsion jacks 146 engage transverse members 147 that span the external framework 141 and the internal framework 142. The base 148 of the propulsion jacks 146 are thrust against ring beams 149, which are added periodically together with additional support bars 151.

Lower portions of the internal framework 142 support the vertical adjustment jacks 145, which control the vertical placement of platform 149. The drive train mechanisms and electric motor 143 are supported by the platform 149.

Roof adjustment jacks are supported by portions of the internal framework 142 and change when desired the vertical placement of roof 152.

The power train mechanisms are identical to those described in connection with FIGURES l through 4. Briefly, the motor 143 is connected to chains or belts 62, which in turn are connected to the shaft mounted speed reducers 67. Internal shafts (not shown) rotate the elongated cutters 85' about their longitudinal axes and also rotate pilot bits 111. An external shaft 71 connects lever -arms 76 and elongated cutters 85 through clutches 7? to provide an intermittent pivotal movement to the elongated cutters 8S upon the actuation of hydraulic cylinder 77. The operation of this part of the invention has been previously described.

The carriage or shield 140 is propelled by actuating propulsion jacks 146, which forces the elongated cutters 85 and pilot bits 111 into the tunnel face 166. When the propulsion jacks reach their maximum extension, anotherring beam 149 is installed with additional support bars 151. Then the bases 148 of the jacks are moved up to another ring beam and thus the cycle is repeated. Of course, while the shield 140 is being thrust forward, roof support jacks 150 are retracted to lower the adjustable roof 152. This prevents interference with forward movement 4of the shield 141D, but when the elongated cutters 85' are being pivoted, roof 152 is thrust against the tunnel roof to eliminate vibrations of the machine, to counteract the reactive forces and to support the roof over the angers.

Thus it may be seen that the construction and opera- -tion of shield 140 and its cooperation with elongated cutters 85 and the pilot bits 111 produce advantageous results due to the increase of rigidity and improved weight distribution.

The elongated cutters 35 are not limited to the auger conguration `of FIGURE 7-A. In FIGURE 7-B, for example, a multiplicity of drag-type cutters 160 are illustrated as being supported on a cylindrical drum 161. In the very loose, unconsolidated formations of the earth such cutters are highly practicable, especially since they have little tendency to clog when moisture is present.

FIGURE 7-C illustrates a multiplicity of rotatable cutters 162 disposed on a series of plates 163 which in turn are aligned in an oblique fashion with respect to the central shaft 164, only one cutter per plate being illustrated although a multiplicity would usually be employed. The placement of the plates 163 is such that the rotatable cutters 162 cover during rotation of central shaft 164 substantially the vertical extent of the shaft 164. Scraper blades are used on this embodiment to wipe cuttings from the path of succeeding cutters.

It is readily apparent that the pilot bits may have many forms Iand thus Ithe type illustrated as having rotatable cutters is not essential. Drag type or disc cutters are within the scope of the invention. The resulting core merely breaks before forward progress of the machine is impeded due to the natural vibrations of the machine.

The advantages of the invention are readily apparent in view of the above description of its structure :and its mode of operation. The use of elongated cutters which rotate about their own longitudinal axes and simultaneously pivot in a plane transverse the tunnel axis, a plane which is substantially vertical when the tunnel is horizontal, overcomes to a great extent the disadvantages of prior art machines. More specifically, the removal of the tunnel face by cutters which move through a vertical plane reduces substantially the longitudinal reactive forces acting against the machine. It will be recalled that after the initial forward thrust, the reactive forces are primarily transverse. The vertical disposition of the elongated cutters reduces the distance traveled by the machine during the initial forward thrust when compared with prior art tunneling machines having horizontally disposed elongated cutters. Moreover, the creating of ledges in the tunnel face by the elongated cutters decreases further the longitudinal reactive forces. In addition, the use of a pair of oppositely pivoting elongated cutters reduces the net transverse force exerted on the machine.

Although specific terminology has been used to add clarity to the description, it is apparent that the invention is not limited to any specific terms but encompasses all equivalent devices which operate in a similar manner t0 accomplish a similar result.

It will be apparent that a horizontal frame of reference has been chosen largely for the convenience it offers in discussing relationships between parts of the specific ernbodiments discussed throughout the foregoing, and that the tunnel or shaft in which the inventionoperates may have a grade or inclination departing widely from theA horizontal. With such grades, parts described above as being vertical will generally no longer be vertical, but will usually be normal to the longitudinal axis of the tunnel, normal t0 the tunnel roof, or the like.

I claim:

1. A mining or tunneling machine for removing incremental layers of rock from a Working face of a tunnel or the like, said machine comprising:

(a) a mobile carriage,

(b) means for propelling the carriage along the tunnel axis into the tunnel face,

(c) a pair of elongated cutters rotatable about their longitudinal axes and mounted upon the forward end of the carriage to pivot about axes substantially parallel to one another and to the tunnel axis, said elongated cutters being disposed with their longitudinal axes transverse the tunnel axis and being provided with peripheral cutting structure over substantially their full axial lengths, and

(d) drive means supported by the carriage and connected to the elongated cutters for rotating them about their longitudinal axes and also for pivoting them in opposite directions about said substantially parallel axes which are parallel to the tunnel axis.

2. A tunneling or mining machine which attacks a tunnel face or the like in a manner to reduce the longitudinal reactive forces that are transmitted from the tunnel face to the machine, said machine comprising:

(a) a carriage with propulsion means for moving the machine incrementally along the tunnel axis into the tunnel face,

(b) a pilot bit rotatably mounted on the end of the carriage to form a pilot hole in the tunnel face,

(c) means supported by the carriage for rotating the pilot bit,

(d) a pair of elongated cutters mounted intermediate the pilot bit land the carriage, said elongated cutters being rotatable about their longitudinal axe-s and pivotable about adjacent axes substantially parallel to one another and to the tunnel axis, said elongated cutters being disposed with their longitudinal yaxes transverse the tunnel axis and being provided with peripheral cutting structure over substantially their full axial lengths, and

(e) drive means connecting the elongated cutters and the carriage for rotating said cutters about their own axes and for pivoting them in opposite directions to cut successive layers from the tunnel face.

3. The machine of claim 2 in which each elongated cutter comprises an auger which in rotation moves the cuttings from the tunnel face toward the pivot point of the cutter, and in which there is a conveyor disposed to receive the cuttings from each auger to move them away from the tunnel face.

4. A tunneling machine which attacks a tunnel face in a manner to reduce the longitudinal reactive forces acting against the machine, which comprises:

(a) a carriage having propulsion means for moving the machine incrementally along the axis of the tunnel into the tunnel face,

(b) at least one pilot bit rotatably mounted at the forward end of the machine,

(c) means supported by the carriage for rotating the pilot bit,

(d) a pair of elongated cutters mounted intermediate the pilot bit and the carriage, said cutters being oppositely pivotable about adjacent axes substantially parallel to one another and to the tunnel axis, said elongated cutters being disposed with their longitudinal axes transverse to the tunnel axis and being provided with peripheral cutting structure over substantially their full axial length,

(e) means for rotating the elongated cutters about their longitudinal axes, and

(f) a pair of lever arms, each of which is pivotally and coaxially mounted behind one of the elongated cutters and disengagedly connected thereto,

(g) means connected to the lever arms for indexing them and the engaged elongated cutters apart to a predetermined angular disposition and for returning the lever arms to an initial position so that indexing may be repeated.

5. The machine of claim 4 in which the means for indexing the lever arms comprises:

(a) a hydraulic cylinder spanning the lever arms to rst spread them apart a predetermined distance from an initial position and then to retract them to the initial position, and

(b) a pair of shafts, each of which connects one elongated cutter to one lever arm, and

(c) ya clutch interposed in each shaft to engage the elongated cutters to the lever arms While the hydraulic cylinder spreads the lever arms apart, said clutch then disengaging the elongated cutter from the lever arm while the lever arm is returned to the initial position.

6. In a mining or tunneling machine having propulsion means and means for moving cuttings rearwardly from the face of a horizontal tunnel, the improvement being a novel cutter arrangement which removes successive vertical sections of earth from the tunnel face, said improvement comprising:

(a) a pair of elongated cutters rotatable about their longitudinal axes and mounted on the forward end of the machine with their longitudinal axes transverse the axis of the tunnel, each said cutter being provided with peripheral cutting structure over substantially its full axial length,

(b) a pair of shafts substantially parallel to each other and to the axis of the tunnel, each of which pivotally connects one of the elongated cutters to the machine,

(c) drive means connected to the shaft for rotating the cutters about their longitudinal axes, and

(d) means for rotating the elongated cutters pivotally in opposite directions in a substantially vertical plane so that the cutters remove successive sections of earth from the tunnel face.

7. The machine of claim 6 in which the means for r0- tating the elongated cutters pivotally comprises:

(a) a pair of lever arms mounted in a substantially vertical plane behind the elongated cutters,

(b) a pair of shafts, each of which connects one lever arm to one elongated cutter,

(c) a ratchet mechanism in each of said shafts to release the elongated cutters from the lever arms, and

(d) means spanning the lever arms to pivot them and the engaged elongated cutters a predetermined amount from an initial vertical position and for returning the lever arms to the initial position while the ratchet mechanism disengages said lever arms from the elongated cutters so that the operation may be repeated to move the elongated cutters successively across the entire tunnel face.

References Cited by the Examiner UNITED STATES PATENTS 207,374 8/1878 Webster 175--91 X 1,516,830 11/1924 Schafer 299-63 X 2,694,563 ll/ 1954 Graham 299-57 X 2,783,036 2/ 1957 Lundquist 299--59 3,128,998 4/ 1964 SibleyV 299-71 X FOREIGN PATENTS 118,437 4/ 1958 Russia.

ERNEST R. PURSER, Primary Examiner. 

1. A MINING OR TUNNELING MACHINE FOR REMOVING INCREMENTAL LAYERS OF ROCK FROM A WORKING FACE OF A TUNNEL OR THE LIKE, SAID MACHINE COMPRISING: (A) A MOBILE CARRIAGE, (B) MEANS FOR PROPELLING THE CARRIAGE ALONG THE TUNNEL AXIS INTO THE TUNNEL FACE, (C) A PAIR OF ELONGATED CUTTERS ROTATABLE ABOUT THEIR LONGITUDINAL AXES AND MOUNTED UPON THE FORWARD END OF THE CARRIAGE TO PIVOT ABOUT AXES SUBSTANTIALLY PARALLEL TO ONE ANOTHER AND TO THE TUNNEL AXIS, SAID ELONGATED CUTTERS BEING DISPOSED WITH THEIR LONGITUDINAL AXES TRANSVERSE THE TUNNEL AXIS AND BEING PROVIDED WITH PERIPHERAL CUTTING STRUCTURE OVER SUBSTANTIALLY THEIR FULL AXIAL LENGTHS, AND (D) DRIVE MEANS SUPPORTED BY THE CARRIAGE AND CONNECTED TO THE ELONGATED CUTTERS FOR ROTATING THEM ABOUT THEIR LONGITUDINAL AXES AND ALSO FOR PIVOTING THEM IN OPPOSITE DIRECTIONS ABOUT SAID SUBSTANTIALLY PARALLEL AXES WHICH ARE PARALLEL TO THE TUNNEL AXIS. 